(1) Field of the Invention
The present invention relates generally to an apparatus for transporting cargo from an aircraft to the ground, and in particular to an improved, disposable cargo container comprised of a box with extendible rotor blades that can be dropped from an aircraft to the ground under adverse conditions without damage to the cargo.
(2) Description of the Prior Art
Numerous circumstances require the transport of various kinds of cargo to inaccessible or remote areas where ground transportation is not possible or timely. These circumstances include both military and peacetime conditions, such as providing emergency food, fuel and medical supplies to victims of natural disasters, fighting of forest fires, etc.
In many instances, the cargo can be transported to the area by helicopter, or dropped from an airplane with a parachute. However, helicopters are not always readily available, and are expensive to operate. Parachutes are also expensive, particularly when used to drop relatively small quantities of cargo, and are usually not recoverable due to the terrain and the conditions under which the cargo is dropped.
Various prior art patents, since at least as early as the 1940s, have proposed an alternative means involving the dropping of containers of small cargo loads from an aircraft without a parachute. Instead, the container is constructed of a disposable box with attached wings or rotor blades that extend outwardly when the box is dropped from an aircraft. The force of the air against the lower surface of these blades causes the blades to turn in the direction of their leading edges, rotating the attached box and creating lift to slow the container's descent.
The following patents are representative of these prior art devices:
______________________________________ Patent Number Inventor ______________________________________ 2,450,992 Sanderson 3,168,267 Ferris 2,324,146 Frazer 2,495,486 Stevenson 3,115,831 Suter ______________________________________
This alternative transport means, while conceptually addressing the need for inexpensive cargo delivery, has apparently found no significant application. This lack of use is believed to be attributable to two somewhat related reasons; cost effectiveness and durability. In order for this type of devise to find a niche in cargo transport, the cost must be low since the container is not recovered. However, prior art designs that could be produced at an acceptable cost do not have the durability to withstand the destructive forces to which they are subjected, resulting in failure of the systems to get their load to the intended destination undamaged. However, the need remains and the basic concept is appealing. Therefore, a disposable aerial cargo container that could be manufactured at an acceptable cost while still having the required strength and durability should be of considerable utility.